title: Effect of a too posterior placement of the tibial tunnel on the outcome 10-12 years after anterior cruciate ligament reconstruction using the 70-degree tibial guide.
abstract: OBJECTIVE
  To examine the relationship between the radiographically assessed placement of the tibial tunnel and the long-term clinical and subjective outcome in anterior cruciate ligament-reconstructed patients.
  
  
  METHODS
  Patients were examined clinically, with subjective score systems and with standardised radiographs 10-12 years postoperatively. Only patients reconstructed with the aid of the 70-degree tibial drill guide were included. A posterior placement of the tibial tunnel was defined as >50% along the Amis and Jakob line (AJL). A high tunnel inclination was defined as >75° in the coronal plane. The possible linear relationships between clinical findings, subjective scores and tibial tunnel placement were investigated.
  
  
  RESULTS
  Eighty-six percentage of the 96 patients were available for examination. Mean tibial tunnel inclination was 71.1° (SD 4.2). No difference was found in subjective scores and knee stability between high (14%) and low (86%) inclination groups. Mean placement of the tibial tunnel along the AJL was 46% (SD 5). Patients with a posterior tibial tunnel placement (24%) had a higher incidence of rotational instability (P = 0.02). Patients with rotational instability (grade 2 pivot shift) had significant lower Lysholm score than those with grade 0 and 1 rotational instability (P = 0.001).
  
  
  CONCLUSIONS
  The use of a tibial drill guide that relates to the femoral roof leads to a posterior tibial tunnel placement (>50% of the tibial AP-diameter) in 24% of the patients. These patients have a significant higher proportion of rotational instability and worse subjective outcome.
  
  
  METHODS
  Case series, Level IV.
authors.affiliation: Surgical Department, Haraldsplass Deaconess Hospital, Pb 6165, 5152, Bergen, Norway, eivind.inderhaug@gmail.com.
authors.forename: Eivind
authors.initials: E
authors.lastname: Inderhaug
authors.forename: Torbjørn
authors.initials: T
authors.lastname: Strand
authors.forename: Cornelia
authors.initials: C
authors.lastname: Fischer-Bredenbeck
authors.forename: Eirik
authors.initials: E
authors.lastname: Solheim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000009:adverse effects* / Q000295:instrumentation; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000209:etiology*; D007719:Knee Joint / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011859:Radiography; D013710:Tendons / Q000637:transplantation; D013977:Tibia / Q000000981:diagnostic imaging* / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult